This invention relates to a sealing assembly for a liquid fountain and, more particularly, a sealing assembly especially adapted for use in a split fountain ink supply system for multi-color flexographic printing.
Although the invention is described in terms of flexographic printing, it will be appreciated that the sealing assembly can be used to advantage in related applications such as coaters, gravure printing, intaglio printing, etc. There has been, however, a pressing need for an effective seal to prevent mixing of two or more different color inks when applied side-by-side from the same fountain. Typical of recent patents illustrating sealing assemblies for split fountain operation are U.S. Pat. Nos. 4,165,685, 4,581,995 and 4,667,595.
According to the invention, a surprisingly advantageous sealing assembly is provided through the use of layer of resilient material such as foam elastomer adapted to abut the arcuate surface of a metering roll to define chambers holding liquid to be applied, viz., ink and wherein the material has a circumferentially extending slot at the surface of the metering roll to accommodate the flow of liquid under pressure. The liquid under pressure is employed in the illustrated embodiment to effect a seal between ink chambers and provide make-up solvent for the ink. This is not found in the art, particularly the above mentioned patents.
Other objects and advantages of the invention can be seen in the ensuing specification.